1. Technical Field
This invention relates generally to portable computers with touch-sensitive screens and rechargeable batteries, and more particularly to a stylus assembly associated with such portable computers.
2. Background Art
Personal Digital Assistants (PDAs) are all the rage. It is nearly impossible to go to a business meeting and not see at least one person whip out a handheld, shirt-pocket sized computer and start tapping away at the screen. US Robotics introduced these devices in the mid-1990s. Today, Palm, Inc. is one of the most prolific suppliers of these devices, which are colloquially called “palm organizers”. Other manufacturers of these devices include Sony and Handspring.
The typical method of using a PDA involves a touch sensitive screen and a pen-shaped object known as a “stylus”. Referring now to FIG. 1, illustrated therein is a PDA 101 and a stylus 100. To enter data into the PDA 101, the user takes the stylus 100 and “writes”, as if with a pen on paper, on the touch sensitive screen 102. The screen interprets the stylus strokes as alphanumeric characters and stores them in the computer's memory. Such a system is described in U.S. Pat. No. 5,231,281 to Duwaer.
Some PDAs use primary batteries, like AA sized alkaline batteries. Other PDAs use rechargeable batteries, like lithium-ion cells. The PDAs with rechargeable batteries include a cradle for charging. To charge the battery, the user places the PDA in the cradle. Electrical contacts in the cradle then meet with electrical contacts in the battery to charge the battery. Such a cradle is shown in FIG. 2.
Most PDAs include some form of fuel gauge. The fuel gauge tells the user how much battery capacity remains. These fuel gauges generally take the form of a picture of a battery on the screen, with a shaded region to indicate the remaining battery capacity. Referring now to FG. 6, fuel gauge indicator 600 is approximately three-fourths shaded, indicating about 75% battery capacity remaining.
A problem exists with this method of fuel gauge indication. This type of fuel gauge is only displayed on the screen when the PDA is turned on. Thus, if the PDA is charging in the cradle, the user does not know how much battery capacity remains without turning the PDA on. Powering the device adds a load to the charger that reduces charging efficiency.
Additionally, the fuel gauge typically is only displayed on the main menu screen. Consequently, if a user is working in his calendar, he must stop working and toggle over to the main screen to see the fuel gauge. Such interruptions in work waste time.
There is thus a need for an improved fuel gauging device.